The invention relates generally to foam gaskets and more particularly to a self-adhesive reinforced foam gasket.
Common weatherstripping for use in the home is well-known. This product is frequently a thick but narrow layer or strip of closed cell plastic flexible foam with a layer of pressure sensitive adhesive on one surface protected by a release liner. The release liner is removed and the weatherstripping is adhered or stuck around a door frame, a window frame, etc. to seal out wind, noise and moisture. This weatherstripping with adhesive and release liner is frequently produced in a very wide sheet (such as 5 feet wide) which is coiled up and slit into a series of thin coils for sale to the consumer. It is believed that in the auto industry it has been known to take a five foot wide sheet of this weatherstripping material, slit it and die cut gaskets in circles, rectangles, etc. for use as a self-adhesive non-reinforced foam gasket in automotive applications such as seals around interior audio speakers, seals around cut-outs in the dash for air conditioning ducting, etc. One problem is that this product easily stretches or distorts during the application process and the fit is poor or imperfect.
To address this problem a prior art product as illustrated in FIG. 1 has been used in the auto industry. FIG. 1 shows a self-adhesive reinforced foam gasket 10 comprising a thick layer of closed cell PVC flexible foam 12, a layer of pressure sensitive adhesive 13, a layer of flexible polyester film 14 (such as Mylar), a layer of pressure sensitive adhesive 16, and a release liner 20 comprised of release paper 22 with a silicone release coating 18.
This product has been produced in wide, approximately five foot, sheets by providing a release liner 20 having a release surface provided by release coating 18, to which is applied a layer of pressure sensitive adhesive 16. A layer of polyester film 14 is then applied to the pressure sensitive adhesive layer 16. On top of polyester film layer 14 is applied pressure sensitive adhesive layer 13, to which is laminated, at room temperature, a previously produced thick layer of closed cell PVC foam 12. In the prior art this product was then die-cut to provide reinforced self-adhesive foam gaskets which were used in the auto industry generally as described above. The polyester film layer prevented the stretching which was a problem with the conventional weatherstripping. The problem with this polyester film-reinforced product is that it is expensive and laborious to produce, and the closed cell PVC foam layer 12 is attached to the polyester film layer 14 by a layer of pressure sensitive adhesive 13, which is not a sufficiently secure way to attach the closed cell PVC foam layer to the polyester film layer. Also, plasticizer in the PVC foam layer 12 tends to bleed through to the adhesive layer 13 and degrade and turn gummy the pressure sensitive adhesive layer 13.
There is a need for a self-adhesive reinforced foam gasket which overcomes the deficiencies in the prior art and a method to produce such an improved product.
A self-adhesive reinforced foam gasket is provided, comprising a release liner having an upper surface which is a release surface, a layer of pressure sensitive adhesive applied to the release surface, a layer of flexible polymeric film applied to the pressure sensitive adhesive layer, and a layer of flexible foam thermally bonded to the flexible polymeric film layer. The gasket has a shape such that it may be used effectively as a self-adhesive foam gasket. A length of material suitable for die-cutting a self-adhesive reinforced foam gasket therefrom is also provided. The material comprises a release liner having an upper surface which is a release surface, a layer of pressure sensitive adhesive applied to the release surface, a layer of flexible polymeric film applied to the pressure sensitive adhesive layer, and a layer of flexible foam thermally bonded to the flexible polymeric film layer. The length of material is at least 8 inches wide and 20 feet long. A method of making the length of material is also provided.